One of devices of this kind is disclosed in International Publication WO 02/064225 A1. In the document, a code representing a group (or set) to which a card belongs is provided on the card by printing or the like. An inspection device in FIGS. 6 and 8 in the document reads a code from each card of a used group (see pages 15 to 17). Based on a code read from a card, the inspection device then judges whether an abnormal card is mixed in the group or not.
The above-mentioned conventional device is conducive to preventing fraud by inspecting whether a card belongs to a predetermined group or not. However, it may be difficult for such a device to detect a fraud on the spot when a fraud is committed.
In Baccarat, for example, cards are dealt to two players (Baccarat is played by a player and a banker as is commonly known, but a banker is called a player in the present application). In a game of Baccarat, a player turns over a card in a manner called “squeeze.” The right of “squeeze” is given generally to a player who made the highest bet. At the time of this “squeeze,” a fraud player substitutes a card by a magician-like technique. It is desirable to be able to detect such a fraud on the spot.
Players could be forbidden to turn over a card in order to prevent a fraud. However, turning over a card by a player is an important factor in the fun of a game of Baccarat. Particularly, having the right of “squeeze” is high status in Baccarat, so “squeeze” is important for the fun of the game.
Though the above example referred to Baccarat, it is also desired to detect a fraud on the spot in Poker or other games as well.
In addition, various inspection devices have been proposed besides the above-mentioned conventional device, but many conventionally proposed devices comprise a mechanism to successively transfer a lot of cards in order to inspect the whole group at a time, and they are relatively large. Under these circumstances, it is required to enable reliable detection of frauds with a simple and inexpensive configuration.